Error in definition of head element

Hi,

I am currently lecturing Web technologies at Goldsmiths, University of
London and, in the process of setting my students a task on DTDs, I appear
to have found an error in the DTD for XHTML, available here

http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd

Specifically, in this DTD, the definition of the head element is given as
follows:

<!ELEMENT head (%head.misc;,
     ((title, %head.misc;, (base, %head.misc;)?) |
      (base, %head.misc;, (title, %head.misc;))))>

However, I think there should be a question mark after the "(title,
%head.misc;)" to indicate that the base element can occur on its own without
a title element. That is, I believe the definition should be as follows:

<!ELEMENT head (%head.misc;,
     ((title, %head.misc;, (base, %head.misc;)?) |
      (base, %head.misc;, (title, %head.misc;)?)))>

Is that right?

Best regards,
Dave Meredith

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David Meredith
dave@titanmusic.com
http://www.titanmusic.com